Seismically-resistant low-cost housing for El Salvador
As the need of appropriate low-cost earthquake-resistant housing is considerably growing in seismically active developing countries, Arup and a local NGO REDES have developed a form of engineering vernacular housing for El Salvador based on traditional housing in Latin America. The design uses a timber frame clad in cane and wire mesh and rendered with cement mortar, with a reinforced concrete foundation and a lightweight roof.
This project was developed from Arup and Engage for Development’s links and experience on the El Salvador Project. Arup developed a design with the local NGO REDES, which wished to develop a seismically-resistant low-cost housing design suitable for El Salvador and cheaper than the alternative of reinforced blockwork. Arup agreed to create a design with REDES based on these core requirements:
- Seismic resistance
- Ease to built
- Ease to maintain
- Locally-soured materials
Sebastian Kaminski, one of the Directors of Engage for Development who works for Arup went on a research trip to Latin America in 2011 sponsored by the Institute of Structural Engineering to research engineered bamboo houses. This research trip led to the development of a prototype house using timber and locally-grown cane plastered in cement mortar.
An experimental study into the seismic behaviour of the individual wall panels was funded by the Institute of Civil Engineers and was conducted at Imperial College London in 2012-2013. Engage for Development also contributed financially to this testing project. Five cyclic in-plane tests on full-scale wall specimens were conducted, each with different variables such as mortar strength and timber frame design. The results of the testing showed that this form of design is capable of resisting large earthquakes and hence can be used in highly-active zones.
In 2012 the El Salvador Project successfully built two of these prototype houses. In 2013, Sebastian Kaminski returned to El Salvador to conduct an evaluation of the houses and was accompanied by Lisa Bunclark, another officer from Engage for Development. The evaluation showed that the houses were well accepted by the locals, and indicated minor improvements that could be made.
Engage is now partly funding a shake table testing of the walls conducted at Cambridge University.